1. Field of the Invention
The present invention relates to an output circuit and, more particularly, to an output circuit comprising a plurality of bipolar transistors for driving a complementary metal-oxide-semiconductor (CMOS) circuit, or a complementary metal-insulation-semiconductor (CMIS) circuit.
2. Description of the Related Art
Conventionally, an output circuit comprising a plurality of bipolar transistors for driving a CMOS circuit has been constituted structured as a Darlington connection type output circuit, which can provide a large amount of driving power, thereby to realize a high speed operation for driving the CMOS circuit by reducing the influences of a stray capacitor existing on an input of the CMOS circuit.
Nevertheless, when a power supply voltage of the output circuit (bipolar transistor circuit) is higher than that of the CMOS circuit and the output circuit outputs a high level signal, the high level signal output from the output circuit may be determined to be potentially higher than the power supply voltage of the CMOS circuit, and thereby erroneous operations of the CMOS circuit may occur. The problems of the output circuit according to the related art will be explained in detail hereinafter.